云南西双版纳的淡水蟹类(软甲纲:十足目:束腹蟹科:溪蟹科)

FRESHWATER CRABS OF XISHANGBANNA, YUNNAN PROVINCE, CHINA(MALACOSTRACA:CRUSTACEA:PARATHELPHUSIDAE,POTAMIDAE)

本文记述西双版纳６种淡水蟹类的种类组成及分布，其中包括二新种的描述。

? During April to May in 1994, an investigation group of animal diversity of Xishuangbanna,Yunnan Province was established. A set of materials of freshwater crustacean were collected.This paper deals with 6 species of freshwater crabs of this area. Among them two new species came acrossed. Descriptions of new species, species composition and distributions of freshwater crabs are reported as below. The types are deposited in the Institute of Zoology, the Chinese Academy of Sciences.Description of new speciesPotamiscus yiwuensis sp. nov. (Figs.19)Holotype ♂(YN9496L95A), paratypes 8♂♂,1♀, Yiwu, Mengla County (214°N, 1015°E), April 29,l994.  Description. Carapace slightly convex fore and apt, surface with fine rugae on anterior portion. Cervical groove shallow and clear, Hshaped groove between gastric and cardiac regions deep and distinct. Postfrontal lobes prominent, postorbital crest sharp. Front slightly deflex, anterior border slightly emarginated medially. Dorsal orbital border ridged, exorbital angle steep, directed forwards, separated with epibranchial tooth by a deep notch. Epibranchial tooth bluntly prominent. Anterolateral border carinated, lined with 1516 granularteeth, last end turning backwards. Third maxilliped with merus about as broad as long, ischium about 1.4 times as long as broad, exopod about reaching proximal l/3 of merus, without flagellum. Chelipeds unequal, carpus with rugae and tubercles on dorsal surface and margins, innerdistal angle with a stout spine, with a short spine at its base; larger manus about 14 times as long as high, about equal to movable finger; without gap between fingers when closed. Ambulatory leg slender, last leg with propodus about 22 times as long as broad, dactylus about l.2 times as long as propodus. Male abdomen triangular, sixth segment about 2 times as broad as long; telson about 1.2 times as broad as long. Median groove of thoracic sternum narrow and deep, interruption between sutures of sternites 4/5, 5/6, 6/7 comparatively narrow, median longitudinal suture of sternites 7 and 8 slightly long. First pleopod not reaching abdominal lock of, subdistal segment about 3l times as long as distal segment, which slender, abdominal lobe sligthly convex at basic half, covered dorsal lobe. Second pleopod with subdistal segment about l.3 times as long as distal segment, which hooked. Female abdomen with sixth segment about 3 times as broad as long; telson about 2.3 times as broad as long. Genital pore, oakseed like in shape, two pores comparatively close. Carapace length of male 218mm, breadth 275mm; of female, length 234mm, breadth 293mm. Remarks. This new species is comparatively close to Potamiscus montosus Dai et al., l975, but smaller sized, anterolateral border arched, exorbital angle steeper, postorbital crest relatively flat. Third maxilliped, with reduced flagellum of exopod, without any trace of flagellum. Male abdomen slightly narrow, first pleopod not very arched outwards, slightly stout. Female genital pore oakseed like, outerlateral margin narrowing not rounded, outerdistal margin prominent inwards.Potamon menglaense sp. nov. (Figs. 1018)Holotype (YN9496l96A), paratypes 13♂♂ (4 juv.), 11♀♀ (7 juv.), Shangyong County (212°N, 1013°E), Mengla, April 23, l994; 6♂♂ l♀, Mangban, April 26, l994. Description. Carapace flat, surface covered with coarse short rugae, cervical groove distinct posteriorly, Hshaped groove between gastric and cardiac regions comparatively deep. Front deflexed, anterior border slightly straight. Doral orbital border ridged, with granules, exorbital angle acutely triangular, slightly bent inwards. Epibranchial tooth short spineshaped, anterolateral border notcarinated, lined with 1213 short spines. Third maxilliped with merusabout l.2 times as broad as long, with ischium about l.6 times as long as broad, exopod about reaching proximal 1/4 of merus, with flagellum. Che